Pop art was born out of a desire to live the American dream – and a belief that the world had become a comic strip. From Andy Warhol's soup cans and signature silver hair to Roy Lichtenstein's Whaam! and Peter Blake's badges, Alan Cumming tells the tale of one of art's most accessible genres

One minute, he's doing Shakespeare. The next, he's starring in Garfield. Does Alan Cumming ever regret saying yes? The star talks to Hadley Freeman about his new shows, his new perfume range – and why he accepted an OBE